<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
<script>
    let a = 12, b = 6, result;
    result = ++a+(b--)-(a--)+a-b+(--b);
    console.log=('a的值是:'+a);
    console.log=("b的值是:"+b);
    console.log=(result);


    let x = 9,y=2;
    x<<=y;  //x = x<<y
    console.log(x);

    let num1 = 123,num2 = '123';
    //等于==符号两端会自动进行数据类型转换
    //全等于===符号两端不会进行数据类型自动转换
    console.log(num1==num2);//true
    console.log(num1===num2);//false
    
    

</script>
</html>